LPI 305-300 Exam With Confidence Using Practice Dumps

The subcommand of virsh that opens the XML configuration of a virtual network in an editor in order to make changes to that configuration is net-edit1. This subcommand takes the name or UUID of the network as a parameter and opens the network XML file in the default editor, which is specified by the $EDITOR shell variable1. The changes made to the network configuration are applied immediately after saving and exiting the editor1.

References:

• 1: net-edit - libvirt.

 Vagrant is a tool that allows users to create and configure lightweight, reproducible, and portable development environments. Vagrant supports multiple providers, which are the backends that Vagrant uses to create and manage the virtual machines. By default, VirtualBox is the default provider for Vagrant. VirtualBox is still the most accessible platform to use Vagrant: it is free, cross-platform, and has been supported by Vagrant for years. With VirtualBox as the default provider, it provides the lowest friction for new users to get started with Vagrant. However, users can also use other providers, such as VMware, Hyper-V, Docker, or LXC, depending on their preferences and needs. To use another provider, users must install it as a Vagrant plugin and specify it when running Vagrant commands. Users can also change the default provider by setting the VAGRANT_DEFAULT_PROVIDER environmental variable. References:

• Default Provider - Providers | Vagrant | HashiCorp Developer1
• Providers | Vagrant | HashiCorp Developer2
• How To Set Default Vagrant Provider to Virtualbox3

The command lxc-checkpoint is used to checkpoint and restore containers. Checkpointing a container means saving the state of the container, including its memory, processes, file descriptors, and network connections, to a file or a directory. Restoring a container means resuming the container from the saved state, as if it was never stopped. Checkpointing and restoring containers can be useful for various purposes, such as live migration, backup, debugging, or snapshotting. The command lxc-checkpoint has the following syntax:

lxc-checkpoint {-n name} {-D path} [-r] [-s] [-v] [-d] [-F]

The options are:

• -n name: Specify the name of the container to checkpoint or restore.
• -D path: Specify the path to the file or directory where the checkpoint data is dumped or restored.
• -r, --restore: Restore the checkpoint for the container, instead of dumping it. This option is incompatible with -s.
• -s, --stop: Optionally stop the container after dumping. This option is incompatible with -r.
• -v, --verbose: Enable verbose criu logging. Only available when providing -r.
• -d, --daemon: Restore the container in the background (this is the default). Only available when providing -r.
• -F, --foreground: Restore the container in the foreground. Only available when providing -r.

The command lxc-checkpoint uses the CRIU (Checkpoint/Restore In Userspace) tool to perform the checkpoint and restore operations. CRIU is a software that can freeze a running application (or part of it) and checkpoint it to a hard drive as a collection of files. It can then use the files to restore and run the application from the point it was frozen at1.

The other statements about the command lxc-checkpoint are not correct. It does not create a clone or an image of a container, nor does it double the memory consumptionof the container. It can work on both running and stopped containers, depending on the options provided. References:

• Linux Containers - LXC - Manpages - lxc-checkpoint.12
• lxc-checkpoint(1) - Linux manual page - man7.org3
• CRIU4